1. Field of Invention
The present invention relates to an organic electroluminescent device and a method of manufacturing the same with an enhanced light-emitting property by selective trapping and fixation of mobile ions.
2. Description of Related Art
Related art organic electroluminescent elements (hereinafter “organic EL elements”) using an organic substance in a light-emitting layer can be used as a spontaneous emission display. A significant issue with organic electroluminescent devices that have such organic electroluminescent elements is the life extension of the elements. Thus, a technology to promote the life extension of the elements is advantageous.
Accordingly, related art electroluminescent elements (organic electroluminescent devices), in which a device to apply a voltage in a direction opposite to the emitting electric field is provided in a device to apply a voltage between an anode and a cathode, is disclosed in Japanese Unexamined Patent Application Publication No. 9-293588, for example. The provision of such devices allows, for example, the orientation polarization of a functional group, which is a part of the organic compound composing the light-emitting layer when emitting, or the ionic polarization of ionic impurities, to be reduced or suppressed in advance by applying a voltage to the opposite direction before emitting light for the first time, and allows ionic impurities (mobile ions) to be prevented from being transferred and diffused into the light-emitting layer. As a result, the light-emitting property could be prevented from degrading or such degradation could be reduced in the light-emitting layer caused by the ionic impurities, and the life extension of the electroluminescent elements (organic electroluminescent devices) could be promoted.